Condition has its own vocabulary and it changes by category. Here is what the words actually mean.
Everywhere
Mint — as made, no wear. Used loosely by optimists; ask for photographs.
Near mint (NM) — a flaw you have to look for.
Excellent / Very good (VG) — visible wear, nothing structural.
Good — confusingly, not good. In most trades this means well-used.
Fair / Poor — complete but damaged.
Sneakers
Deadstock (DS) — unworn, with original box and accessories.
VNDS — "very near deadstock", worn once or twice.
Beaters — worn hard and sold as such.
Cards and comics
Raw — not professionally graded.
Graded — assessed by a grading company and sealed in a holder with a number.
Centring — how evenly the image sits. Often the single biggest factor.
Trimmed — cut to improve the edges. A fake, in effect; measure against the standard size.
Restored — repaired, usually on a comic. Must be declared and heavily affects value.
Coins
Uncirculated — never used as money. Not the same as shiny.
Cleaned — polished at some point. Reduces value, often a lot, and cannot be undone.
Patina / toning — the surface age has given it. Desirable; do not remove it.
Records
Sleeve and disc are graded separately. VG+ sleeve with a NM disc is normal and should be stated as two grades.
Seam split — the sleeve edge has opened.
Antiques and furniture
Original — unrestored, as it has survived.
Restored — repaired sympathetically.
Married — two pieces from different objects joined together. Must be declared; it is a large reduction.
Textiles
Handloom vs powerloom — a difference in how it was woven, visible in the irregularity.
Vintage — old enough to be a style, not necessarily old enough to be an antique.
The rule underneath all of it
A word is worth less than a photograph of the flaw. If a seller uses a grade, ask what it is based on — and a seller who describes the flaw is telling you what their grades are worth.